For those of you who don’t know, FOAF stands for Friend of a Friend. It is a social network description format based on RDF.

If people where to have their FOAFs encoded on RFID tags (along with User ID) and placed inside their watch (think Casio G-Shock) then whenever FOAF-watch-wearing users come within the coverage area of an RFID scanner network (in the real world) the network would detect if they have 1st, 2nd or 3rd-degree friend in common and transmit a signal to their watches which would in turn beep and display the name of the party in common as well as the name of the second party and their location relative to a given node within the RFID scanner network.